I found this tutorial in Python very helpful for getting access codes:
This tutorial uses Microsoft Graph (which covers several Microsoft products including Microsoft Outlook) rather than the outlook REST API (which covers just Outlook).
https://learn.microsoft.com/en-us/outlook/rest/python-tutorial
At first, I thought setting up a Django server was overkill. Then I realized that I wanted a way for my Python instance to capture the access code after going through single-sign-on. (I MUST use my browser for single-sign-on because my institution uses multi-factor authentation.) Having a Django server is a natural way to do this.
So I created a new PyCharm Django project (which is straight-forward in PyCharm) and began following the tutorial.
I found it essential to continue following the tutorial all the way through displaying my emails to avoid getting authentication errors -- deviate from the tutorial, and I got error messages (such as this one) that were unpenetrable.